While it’s sometimes true that splitting a big change into smaller pieces can be hard, it’s still worth it. Whenever you’re going through a long iteration, you aren’t getting feedback. You’re working in a bubble, and you might be running headfirst into a wall.

Short iterations are important because the iteration is your feedback loop. Once you finish an iteration you can get feedback on it. Getting it quickly is important, because it allows you to adjust at a lower value stage. Changing direction early is always easier than later.

The feedback comes from multiple sources by the way. You can get feedback from your colleagues, from tests, from seeing an idea work in production, from users or many other ways. Some issues and improvements are hard to predict, and feedback helps surface those quicker. That’s why short iterations are important. Feedback and adjusting based on that feedback is the goal.